#include <iostream>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <set>
#include <bitset>
#include <utility>
using namespace std;

#define mm(a, n) memset(a, n, sizeof a)
#define mk(a, b) make_pair(a, b)

const double eps = 1e-6;
const int INF = 0x3f3f3f3f;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;
typedef pair<double, double> PDD;
typedef pair<LL, LL> PLL;
typedef pair<int, LL> PIL;

inline void quickread() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

string str, cur;

inline void solution() {
    cin >> str >> cur;

    // 全部转换成大写 方便后续操作
    transform(str.begin(), str.end(), str.begin(), ::toupper);
    transform(cur.begin(), cur.end(), cur.begin(), ::toupper);

    unordered_set<char> st;
    vector<char> res;

    for (auto& s : str) 
        if (cur.find(s) == -1 && !st.count(s))  // cur.find(s) == string::npos
            st.insert(s), res.push_back(s);

    for (auto & r : res) cout << r;
    cout << endl;
}

int main() {
    freopen("input.txt", "r", stdin);
    quickread();
    solution();
    return 0;
}